中国沿海地区热带气旋危险性分析

Hazard Analysis of Tropical Cyclone in Coastal Areas of China

基于1980—2016年的西北太平洋热带气旋尺度资料,采用2种方法分析了热带气旋灾害的危险性。第一种方法根据热带气旋的风圈半径,用GIS生成了每个气旋的影响范围,对于登陆中国沿海的227个热带气旋,用叠加法得到了其影响范围与频次。第二种方法侧重热带气旋引发的风暴潮灾害,用潮位模型估算了热带气旋登陆时的潮位数据,提出了H3指标,该指标用潮位、风速和中心气压3个因子计算潮位点的风暴潮危险性,并根据H3指标得到了海岸线的危险性综合指标。分析结果表明,福建、广东两省受热带气旋的影响最为严重。37 a间,福建省有80%的面积(约9.8万km^(2))受热带气旋影响的频次超过20次;广东省则有70%的面积(约12.6万km2)受热带气旋影响的频次超过20次。受风暴潮危害大的海岸线主要位于广东、广西、福建、浙江四省,危险性指标在30以上的有广东的湛江市、茂名市、江门市、阳江市和珠海市;广西的北海市、防城港市和钦州市;福建的福州市以及浙江的台州市和温州市。

Based on tropical cyclone data in the northwest Pacific from 1980 to 2016,we used two methods to analyze the risk of tropical cy-clone disasters.The first method used GIS to generate the influence range of each cyclone based on the wind circle radius.For the 227 tropical cy-clones that landed on the mainland of China,the influence range and frequency were obtained by GIS overlay method.The second method fo-cused on storm surge disasters caused by tropical cyclones,used tidal model to estimate the tide level at the time of tropical cyclone landfall,put forward a H3 index which calculating the storm surge risk by three factors of tide level,wind speed and central air pressure,and according to the H3 index,obtained a comprehensive index of coastline hazard.The analysis results show that Fujian and Guangdong Provinces are the most seri-ously affected by tropical cyclones.During the 37 years,80%area of Fujian Province(about 98000 km^(2))has been affected by tropical cyclone more than 20 times,70%area of Guangdong Province(about 126000 km2)has been affected by tropical cyclones more than 20 times.The coast-lines which greatly affected by the storm surges are mainly located in the four provinces of Guangdong,Guangxi,Fujian and Zhejiang,and with risk indicators above 30 including Zhanjiang,Maoming,Jiangmen,Yangjiang and Zhuhai in Guangdong Province,Beihai,Fangchenggang and Qinzhou in Guangxi Province,Fuzhou in Fujian Province,Taizhou and Wenzhou in Zhejiang Province.